Con. Battery can't be removed. Memory can't be expanded. No support for Adobe Flash video sites. For FaceTime to work, both parties need to be using the new iPhone and have Wi-Fi access. Occasional dropped calls.

HOW MUCH DOES IT ALL COST?

First-time iPhone buyers in the USA or those eligible for an upgrade AT&T has relaxed upgrade requirements pay $199 for a 16-gigabyte iPhone 4 or $299 for 32 GB. Both come in white or black, and you'll have to sign up for a two-year contract with AT&T. Apple is also selling an 8-GB version of the previous model, the iPhone 3GS, for $99 with a two-year AT&T contract.

AT&T has two data pricing options. You get 200 megabytes of data for $15 a month, which AT&T says is enough for about 1,000 e-mails without attachments, plus 150 e-mails with attachments, plus 400 Web pages, 50 photos uploaded to social-media sites and 20 minutes of streaming video. An extra 200 MB for a cycle costs $15.

An extra $20 monthly buys tethering, or the ability to use the iPhone as a broadband modem for laptops, netbooks and other devices. Regrettable exception: You can't use the iPhone as a modem for an iPad.

All this is on top of your regular voice minutes: $40 a month for 450 anytime minutes, $60 a month for 900 minutes or $70 a month for unlimited minutes. Text messages are extra: $5 a month for 200 messages, $15 for 1,500 or $20 for unlimited messages.

Meanwhile, AT&T has said that while it's on track to deliver phones to buyers who ordered the device on June 15, others will now have to wait until June 29, when it hits AT&T retail stores and online outlets. For information on other retailers, including Best Buy, RadioShack and Walmart, check with your local store.

By Ed Baig

The iPhone has had an enormous impact in the three years since Apple's original smartphone exploded onto the scene. Its fancy touch-screen established that a physical keypad or keyboard were no longer de rigueur for cellphones. Its dazzling browser proved you don't have to compromise the way you experience the Web on a mobile device. And the App Store popularized third-party add-on programs on a handheld computer, to the tune of more than 225,000 apps and more than 5 billion downloads.

Even its most strident critics — folks frustrated by AT&T's dropped calls, people who never cozied up to a multitouch display — must concede that the iPhone is the smartphone by which others are measured.

The new iPhone 4 I've been testing for about a week and a half — along with the major refresh of the mobile operating system software at the core of recent models — demonstrates once again why Apple's handset is the one to beat, even as it faces fierce competition from phones based on Google's Android platform, among others.

Apple announced the iPhone 4 at its Worldwide Developers Conference earlier this month. After the customary hype that followed, iPhone 4 will hit stores Thursday morning, though some customers who have ordered the device will receive them earlier. Judging by 600,000 early orders, iPhone 4 is already a runaway hit.

Buyers won't be disappointed. The killer feature is what Apple calls FaceTime video chat. The promise that you and the person you're talking to on a phone can gaze into each other's eyes dates back to when LBJ occupied the White House. No one has really nailed video calling through the years, at least not the way Apple has nailed it here, with certain limitations. FaceTime is as simple as making a regular call. To help to accomplish this neat stunt, iPhone 4 adds a front-facing camera that complements the more traditional, and improved, camera on the back.

There are other iPhone 4 features worth crowing about: high-definition video recording, super-crisp display, a handsome and thin stainless steel and glass design. Apple says the glass is chemically strengthened to be 20 times stiffer and 30 times harder than plastic. To reinforce the point, an Apple executive dropped it in front of me. The phone was undamaged. Inside is an A4 processor, the power-efficient chip used in the iPad.

As part of the latest mobile operating system, what Apple calls iOS 4, you get bolstered e-mail features, a better way of organizing apps, search suggestions in mobile Safari and multitasking. IOS 4 is compatible with the iPhone 4, iPhone 3GS and iPhone 3G, though not all features work across all the devices.

Multitasking, which lets you run more than one application at a time, is a catch-up feature that works on the iPhone 4 and iPhone 3GS only. Apple claims to have come up with a multitasking approach that avoids draining the battery or system resources.

Critics are left with reasons to whine. Apple's public dissing of Adobe Flash means you'll still come upon Web video sites that don't make nice with the iPhone. I had a few dropped calls. The battery still isn't user-replaceable, and there's no slot for expanding memory.

Highlights of iPhone 4 and iOS 4:

FaceTime: simple as tapping a button

This gleeful feature promises that grandparents can meet the newborn from afar, and business travelers can look in on the kids from the road.

Video calling is as simple as tapping a FaceTime button next to a Contacts entry when you initiate a call or tapping a button once you're on a regular voice call. You can seamlessly switch from front to rear camera and back during a call, allowing you to share your surroundings with a caller. FaceTime works in portrait and landscape mode; landscape is useful if you want to get more than one person in a scene. Either way, you'll see your own mug in a small picture-in-picture window.

Now the caveats: Both you and the person you're talking to need an iPhone 4, though Apple hopes to make FaceTime a standard that would permit video calling across numerous devices.

Both parties need to be connected to Wi-Fi. FaceTime doesn't work over AT&T's cellular network, even though you typically make the initial call through AT&T. It takes a few seconds once you tap the FaceTime button for AT&T to hand the call over to the FaceTime application. After it does, you're no longer exhausting any of your AT&T cellular minutes. Side benefit: Besides video, you get far better audio quality. That said, the voice quality on regular AT&T calls wasn't bad, aided by a second microphone that helps suppress background noises.

Though you can make a FaceTime call after beginning an AT&T voice call, you can't do it in reverse. To go back to an audio call, you must end your FaceTime session and redial.

I was impressed with the quality and ease of FaceTime calling, though the experience seems to depend on a strong Wi-Fi connection. I encountered momentary hiccups talking with a caller in Europe and on calls in which I was on the edge of decent Wi-Fi.

Photos and video: camera has come far

I've never been wild about the camera on the early iPhones, but the main camera on the new iPhone has come far. The iPhone 4 sports a 5-megapixel autofocus camera with a 5x digital zoom and — first for an iPhone — an LED flash. I took several decent pictures in low light but had some grainy results, too. It's not a great camera for capturing fast-moving action. Close-ups taken with the 5x digital zoom, which is an iOS 4 addition, were so-so.

As before, pictures taken with the iPhone camera are "geotagged" with the location of where they were shot. But now as part of iOS 4, the iPhone plots these on a map inside the Photos app via a feature called Places.

If you sync the iPhone with iPhoto on a Mac, you can also take advantage of a Faces feature that lets you look at all the pictures that have a particular person in them.

The second, front-facing camera on the iPhone makes it a snap to capture self-portraits without flipping the device around.

The iPhone 4 can also take high-definition video footage, up to what techies refer to as 720p. And the tap-to-focus feature, previously used on the 3GS for still images, can also be employed when you're capturing video. You tap the screen in the area you want the iPhone to focus on. As on the 3GS, you can trim video right from the device.

I sampled Apple's $4.99 version of iMovie for the iPhone, which lets you add themes, music, audio and transitions to your video. I found it a little clumsy to use, however, and for some reason the app misidentified the location where certain footage was shot.

iBooks: read some digital books

Apple introduced iBooks with the iPad. It's brought the app and its virtual iBookstore to the iPhone through iOS 4. You'll have to download the free app from the App Store. Books you buy in the iBookstore land on a handsome depiction of a wooden bookshelf; Apple says more than 60,000 books are available. You can change pages by tapping a page or dragging the upper right or bottom right edges of a page; pages curl like a real book. You can sync bookmarks, notes and your place in a book with your copies of the book on an iPad.

You can change fonts and type size, but because of the iPhone's far smaller display compared with the iPad (3.5 inches vs. 9.7 inches), you don't get the same dramatic impact — though on the iPhone 4 especially, the text is supercrisp and sharp through what Apple calls Retina Display technology. One other difference: When you turn the iPhone to landscape, you don't get the same two-page view you get reading an iBook on the iPad.

Multitasking: apps need to be tweaked

You'll need an iPhone 4 or 3GS to take advantage of multitasking. Older iPhones don't have the resources to pull it off. The beauty of multitasking is you don't have to shut down an app when you want to launch another.

Audio apps such as Pandora continue to play music while you surf or check e-mail. Navigation apps continue to update your location while you listen to music. You'll also be able to receive calls from VoIP providers such as Skype, even when the app isn't open. Previously, only Apple's own programs, notably iTunes, could multitask on the iPhone.

That said, app developers have to tweak their software before you can multitask on the iPhone and most, including Skype, haven't done so yet. Still, I successfully tested multitasking with apps such as Pandora, Evernote and Dropbox.

You can summon the iPhone's new multitasking interface when you double-click the Home button. A tray, or shelf, appears with icons for all the most recently used apps, making it a cinch to switch among them. Apps pick up where you left off. Apple preserves battery life by temporarily freezing the apps that aren't in use, though they can be brought back to life quite quickly.

To be sure, multitasking on the iPhone isn't like multitasking on a PC or Mac. Among other things, you can't display more than one app at a time in different windows on the screen.

Folders: a new way to organize apps

Anyone with screen after screen of icons will appreciate Folders. This new way to organize your apps arrives with iOS 4. You can stash up to a dozen like-minded apps into Folders — up to 2,160 apps in 180 folders.

To create one, drag one app on top of a similar program. Apple takes a stab at naming the folder based on the category of the apps you're putting in there. You can change the name.

To launch an app inside a Folder, tap the Folder icon and then the icon for the app inside. I set up folders for music, radio, navigation, health, travel and other categories.

Because of the 12-app limit per folder, you may find yourself creating folders for subcategories. Along those lines, I have folders for arcade games, kids' games and word games.

E-mail: one-stop shopping for messages

The major addition here is a unified inbox across all your e-mail accounts, including the Microsoft Exchange account you use for work. So you don't have to open and close each individual e-mail account to see messages that have come in, though you can, of course, do so.

The other welcome addition is mail threading, in which messages are lumped together by conversation.

Battery: it's larger, and it lasts longer

Apple improved the battery life on the iPhone 4. It uses a larger battery, for one thing. Pounding it pretty hard, I still sometimes reached low-battery warnings late in the day, so having chargers where you work as well as where you live isn't a bad idea.

Take any manufacturer's battery claims with a grain of salt, but Apple says you'll get up to seven hours of talk time on the 3G network compared with five hours on the 3GS. You'll get up to six hours of Internet use on 3G or up to 10 hours on Wi-Fi, each an hour improvement over the 3GS.

Video playback of up to 10 hours and audio playback of up to 40 hours are rated the same.

As with previous iPhones, the latest model breaks new ground. FaceTime video calling on the iPhone 4 is one of those cool "seeing is believing" features, and it arrives on top of several across-the-board enhancements. And iOS 4 is a mostly terrific software upgrade.

Cutting through the hype, Apple has given longtime diehards, and first-time iPhone owners, plenty to cheer about.

E-mail: ebaig@usatoday.com. (Baig is co-author of iPhone for Dummies, published by Wiley.)

To report corrections and clarifications, contact Standards Editor Brent Jones. For publication consideration in the newspaper, send comments to letters@usatoday.com. Include name, phone number, city and state for verification. To view our corrections, go to corrections.usatoday.com.

Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more.